Yūko Maruyama is a Japanese voice actress and actress born on April 4, 1969, in Kanagawa Prefecture. She is affiliated with the theatrical troupe and agency Super Eccentric Theater (SET).

Her career in voice acting includes work across various anime television series, films, and original video animations. Among her notable roles, she voiced the character Monitamon, as well as Shakkoumon and Clockmon, in the Digimon Xros Wars franchise. Her film credits include the role of Kawauso in the 2008 theatrical film Gegege no Kitarō: Nippon Bakuretsu!!, which aligns with one of the example roles provided. Additionally, she provided a voice in the 2015 film The Boy and the Beast.

Her extensive voice acting portfolio spans a range of other productions. In television anime, her credits include roles in No Rain, No Rainbow (as Oba-chan), And Yet the Town Moves (as Oba-chan), Hidamari Sketch x Honeycomb (as the landlady), and The Strange Case of a Lecture (as Ichikawa's mother). She has also been involved in original video animations and other media formats throughout her career.

Beyond her voice work in animation, Maruyama has maintained a parallel career as a stage actress. Her debut performance was in the 1989 stage production DIRT, which served as her entry into the entertainment industry after passing an audition for Super Eccentric Theater. She has continued to appear in various theatrical productions with the company. In addition to acting, she has engaged in musical activities, including being part of the vocal unit "Kinkan" with fellow SET member Shiroko Shirata, with whom she released a major debut single in 1999.